On 19 December 2013 11:58, Andrew Cowie <andrew@operationaldynamics.com> wrote:

I have a Map. It's a lovely Map, with keys and values and everything.
It's not _that_ large. Few 10s of MB at most. Unfortunately, I need to
persist it somewhat reliably.

I'd somewhat like to avoid having to use an external database (obviously
a key/value store like Riak would work, but that's a major dependency to
impose on the system) so I'm wondering if there is a low tech way to do
this.

I can control concurrent access to the file (or whatever), and the file
system is robust. So that part is fine. I just need to externalize the
map.

I'm wondering if just using cereal or so would be sufficient (there is a
Serialize instance, of course), or whether I should be using some
acid-state thing, or a Haskell binding to gdbm, or sqlite, or...

Any suggestions?

Do you need concurrent access to the on-disk map, or will you just load, modify, then store explicitly?

Do you care about data corruption, eg. if your program/hardware fails during writing?

I'd probably just use sqlite via something like esqueleto, because it's easy to inspect the stored data outside of your program.

Conrad.